Louis Kat was married and had two children. The family lived at 166 Vrolikstraat in Amsterdam. He was a diamond merchant. In 1941 during a diamond transaction (presumably an illegal one), he became the victim of an agitator and was arrested. A batch of diamonds was confiscated in the process. Louis Kat reached Westerbork on 9 January 1943. On 11 January 1943 he was deported to Auschwitz, where he was killed on 30 April. Louis Kat's wife and children went into hiding and survived the war.
The archive of the Stichting Sieraden-Comité contains a list of stolen items of jewelry.
NIOD, Records Stichting Sieraden-Comité, film 580, nr 1926, file 52
In addition, Jokos files (numbers 32451, 5357) on this family or other family members are at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.